日本猴脑内阿片μ-受体样免疫反应物质的分布:Ⅱ.颈、胸、腰、骶段脊髓及后根节(英)

DISTRIBUTION OF μ-OPIOID RECEPTOR-LIKE IMMUNOREACTIVITY IN THE BRAIN OF THE JAPANESE MONKEY(MACACA FUSCATA):Ⅱ.ROSTROCAUDAL NEURAXIS OF SPINAL CORD AND DORSAL ROOT GANGLIA

通过应用识别大鼠阿片μ-受体（MOR）C末端30个氨基酸残基特异性位点的豚鼠抗体，本文对日本猴颈、胸、腰、骶段脊髓和背根节内MOR-样免疫反应物质的分布形式和特点进行了免疫组织化学研究。结果如下：强染色MOR－Li密集分布于脊髓吻尾全长的背角浅层，主要以Rexed第二层内侧部为主。在脊髓背角深层和中央导水管周围区域内也可见中到低等数量的MOR-Li标记。在脊髓背角浅层，MOR-Li广泛分布于Ⅰ、Ⅱ层内神经毯和神经元突起，但似乎只分布于第Ⅱ层神经元胞体。背角深层（Ⅳ－Ⅵ层）有些神经元的胞体和树突也有较强的MOR－Li染色。MOR－Li在背根入髓区和Lissauer's氏束中分布密集且染色强。在后根节，MOR－Li主要分布于中、小细胞，其中MOR－Li阳性小细胞约占65.71％（1018／1562），直径平均为29.50±0．11μm（17．31～34．88μm），中等细胞约占34．19％（534／1562），直径平均为39．04±0．14μm（24.01～49．86μm），而MOR－Li阳性的大细胞只占0．64％（10／1562），直径平均为59.00±2.35μm（51．09～71．39μm）。本结果揭示猴脊髓内阿片肽主要通过突触前和突触后两种方式发挥镇痛作用，除此之外，还可能通过作用于外周伤害性感受器部位的MOR发挥镇痛作用。

By using anti-μ-opioid receptor (MOR) antibody which recognized rat MOR1 specific site (C-terminal residues 369-398), distributions of MOR-like immunoreactivity (Li) in the rostrocaudal neuraxis of the spinal cord and dorsal root ganglia (DRG) of the Japanese monkey(Macaca fuscata) were examined immunohistochemically. MOR-Li was densely distributed in the superficial layers of dorsal horn with predominance in the inner part of lamina Ⅱ throughout the spinal cord. Moderate to sparse density of MOR-Li was seen in the deep layers of dorsal horn and the region surrounding the central canal. In superficial layers,MOR-Li was expressed in neuropil, processes of neurons of both lamina Ⅰ and Ⅱ, while in perikarya only in lamina Ⅱ (substantia gelatinosa). Some neuronal cell bodies with MOR-Li were also observed in laminae Ⅳ-Ⅵ. MOR-Li was also densely distributed in the dorsal root entry zone and the Lissauer's tract throughout the spinal cord. In DRGs, MOR-Li was intensely expressed in a class of cells predominantly with small (Diameter Mean±S. E.: 29. 50±0. 11μm, 17. 31-34. 88 μm) (65. 17%, 1018/1562) to medium (39. 04±0. 14 μm, 34. 01-49. 86 μm) (34.19%, 534/1562) size, whereas occasionally in cells with large(59. 00±2. 35 μm, 51.09-71. 39 μm) (0. 64%, 10/1562) size. This result suggests that opioid peptides may exert their analgesic functions through MOR presynaptically as well as postsynaptically in the dorsal horn and through MOR of nociceptors in peripheral sites.